Patents by Inventor Masaki KIYOKAWA

Masaki KIYOKAWA has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11445154
    Abstract: A laser drive apparatus is provided with a digital to analog converter including current sources of a number corresponding to a bit number of a digital input code and switches of a number corresponding to the number of bits. The digital input code is converted from input video data, and provided to a DA converter, that generates RGB drive currents for a laser scanning type image display apparatus driven by the laser drive apparatus, and output currents from current sources are weighted in accordance with bits of the digital input code. A ratio of each of the output currents from each of the current sources to a load capacity of a driver having each of current mirror circuits is identical for all bits corresponding to each of the current sources, and the current mirror circuits is configured to distribute load capacity of the driver circuit.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: September 13, 2022
    Assignee: Nisshinbo Micro Devices Inc.
    Inventor: Masaki Kiyokawa
  • Publication number: 20220006985
    Abstract: A laser drive apparatus includes a DA converter including current sources of a number corresponding to a bit number of a digital input code, and switches of a number corresponding to the number of bits. The switches are connected to the current sources and selectively switch presence or absence of output of a control current therefrom, and the DA converter outputs control currents corresponding to the digital input code as output respective currents from the switches. The laser drive apparatus includes a driver circuit including current mirror circuits that generate a drive current corresponding to each output current based on each output current to drive a laser diode. In the driver circuit, the current sources are divided into current source sets, to which the current mirror circuits are connected via the switches, and generate a drive current corresponding to each output current to drive the laser diode.
    Type: Application
    Filed: December 21, 2018
    Publication date: January 6, 2022
    Applicant: RICOH ELECTRONIC DEVICES CO., LTD.
    Inventor: Masaki KIYOKAWA